Automobile antenna



Sept. l0, 1940. 1 .sToNE,JR

AUTOMOBILE ANTENNA Filed June '7, 1938 INVENTOR. Aww/V615 o/vfJ/.z BY YI MdKTORNIAH Patented Sept. 10, 1940 UNITED STATES PATENT OFFICE Claims.

Other objects of the invention are to providel signal means which willnotify the driver whether the antenna is in the vertical or foldedposition; to provide means for minutely and accurately adjusting thelength of the antenna so that it may be accurately tuned into the inputcircuit of the radio; and to provide latch means which hold the antennarigidly vertical until it contacts an obstruction to prevent its beingfolded by the wind.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efciency.These will become more apparent from the following description.

In the following detailed description of the invention reference is hadto the accompanying drawing which forms a part hereof. Like numeralsrefer to like parts in all views of the drawing and throughout thedescription.

In the drawing:

Fig. 1 is a perspective View illustrating the invention in place upon anautomobile.

Fig. 2 is a vertical section therethrough.

Fig. 3 is a detail view illustrating the mounting bracket of theantenna.

Fig. 4 is a detail section through the signal switch illustrating itsassociation with the an- 40 tenna.

Fig. 5 is a detail view illustrating an alternate form of the antenna inwhich the projected length thereof may be adjusted.

In Fig. l a typical automobile is indicated at ID, The improved antennamay be attached at any desired position on the automobile I0. It ispreferred to attach it to the forward mid-position of the roof asillustrated.

The antenna is supported from a base plate I I which can be attached tothe automobile in any desired manner. Two supporting arms I2 extendupwardly from the base plate I I to pivotally support the antennaproper.

The antenna consists of a tip member I3 which is telescopically slidablewithin a tubular inter- (Cl. Z50-33) mediate section I4. Theintermediate section I4 is also telescopically slidable Within a lowerinsulating tube section I5.

The lower section I5 is formed of bakelite, hardfrubber, fiber, or otherelectric insulating material and is mounted by means of a pair of clampmembers I S clamped thereto by means of suitable clamp bolts I'I. Eachof the bearing members carries a bearing stud I3 which is rotatablymounted in a bearing in one of the 10 arms I2.

A compression spring I9 in the section I4 constantly urges the tipmember I3 upwardly. The outward movement thereof is limited by means ofan enlarged extremity 20 which contacts a cap 15 member 2l.

The intermediate section I4 is constantly urged upwardly by means of acompression spring 22 positioned within the tube I5 and contacting anenlarged extremity 23 on the-section I4.

The lower extremity of the section I5 carries a counter-weight 24 whichpartially closes the tube I5 at the bottom thereof to provide a shoulderfor the support of the spring 22. The counter-weight 24 is of suiilcientweight to maintain 25 the entire antenna vertical.

An antenna lead wire 25 extends through the base plate II into the tubeI5 where it connects with a tension spring 26 which extends upwardly toa connection with the intermediate sec- 30 tion I4.

The spring 2B acts to maintain the lead wire 25 tight at all times toprevent bending or wrinkling thereof, but is not strong enough tocollapse the spring 22. The purpose of the insulating tube 35 I5 is toposition the metallic portion of the antenna abov'e the metallic top ofthe automobile ID to avoid the shielding eiect of the latter.

It can be readily seen that, as the automobile is driven under a lowobstruction such as through 40 the doorway of a building, the entireantenna will fold or tilt backwardly, as indicated by the broken linesin Fig. 1. After the obstruction is passed, the weight of thecounter-weight 24 assisted by the tension spring 26 will immediately 45bring the antenna to a vertical position. Should the car be backed whilethe antenna is in the folded back position, the section I3 will beforced into the section I4 and the section I4 will be forced into thetube I5 allowing the car to pass 50 under the obstruction after whichthe tubes will spring back to position and the antenna will resume itsvertical position.

For police cars, the antenna circuits must be accurately tuned with theradio for the desired 55 wave band. A slight increase or decrease in thelength of the antenna effects the resonance of the receiver to and fromthe desired broadcast band. Therefore means are provided, as shown inthe alternate form of Fig. 5, for obtaining an accurate adjustment ofthe length of the metallic portion of the antenna so that the inputcircuit may be tuned to proper resonance. This is accomplished byemploying a tapered tip-section 2l and splitting the upper extremity ofthe intermediate section as indicated at 2S. A cap member 35, theinterior of which is taper threaded engages the upper extremity of theintermediate section. As the cap member is tightened, it squeezes thesplit extremity inwardly so that it will engage the taper of the taperedtip section 2 at any desired point to limit the upward movement of thetip section. Therefore, by tightening or loosening the cap member 35,the overall length of the entire antenna may be accurately and minutelypre-set.

t is also very essential in police work that the operator be informed atall times whether the antenna is in the vertical receiving position sothat he will know his receiving set is in condition for receivingincoming signals. This is accomplished in the present invention byproviding a signal circuit which operates whenever the antenna is foldedto give an indication thereof to the operator.

In the particular embodiment illustrated, a press button switch member'3a is mounted below the counter-weight so as to be contacted therebywhen the antenna is in the vertical position. The switch member 2Qcloses contact between a pair of Contact members whenever it is releasedby the swinging of the antenna from the vertical position. Thesecontacts are in circuit with an indicating light 3l, or an audibleindicator 32, so that the operator will be immediately informed that theantenna is down.

It is preferred to have the head of the switch member rounded and toprovide a receiving depression 33 on the counter-weight into which thehead will be forced by means of a switch spring 3d when the antenna isvertical. This enables the switch to serve a double purpose since italso acts as a resilient latch member to hold the antenna vertical andto prevent it from swinging or swaying in the wind until it actuallystrikes an obstruction.

While the invention has been described as a receiving antenna, it formsan unusually efiicient sending antenna where two-way radios areemployed. Should the antenna be in the folded position, broadcastingwould be impossible due to the shielding effect or" the roof. Thereforthe signal is especially valuable in broadcasting.

While a specific form of the improvement has been described andillustrated herein, it is desired to be understood that the same may bevaried, within the scope of the appended claims, without departing fromthe spirit of the invention.

Having thus described the invention, what is claimed and desired securedby Letters Patent is:

l. A radio antenna for automobiles comprising: a base member; oppositelypositioned bearings supported from said base member; a rst tubeextending upwardly from said base member and mounted in said bearings sothat it may swing in a vertical plane; a second tube telescopicallyslidable within said rst tube and extending upwardly therefrom; springmeans for holding said second tube in the extended position; acounter-weight mounted on the lower extremity of said first tube belowsaid bearings to act by gravity to hold said tubes in the verticalposition; a switch member positioned to be opened by contact with saidcounterweight when said antenna is in the vertical position; and asignal device in circuit with said switch member to give an indicationwhen said antenna is other than vertical.

2. A radio antenna for vehicles comprising: a base member; bearingscarried in two oppositely positioned supporting arms extending upwardlyfrom said base member; an antenna member mounted in said bearings sothat it may swing in a vertical plane; a reciprocal weight mounted onthe lower extremity of said antenna member below said bearings to act bygravity to hold said antenna in a vertical position; an antenna leadwire extending upwardly into said antenna; and a tension spring inelectrical series with said wire for maintaining said wire taut.

3. A vehicle radio antenna comprising: a bearing bracket member forattachment to said vehicle; an elongated antenna member hingedly mountedintermediate its extremities in said bracket to swing in a verticalplane; a counterweight rigidly secured to the lower extremity of saidantenna member to maintain the latter normally Vertical; a headedplunger member; and spring means for urging the head of said plungermember into the path of movement of said counterweight, the latterhaving means for receiving said head when said antenna is in thevertical position, to resist swaying of said antenna member under themovement of said vehicle.

a. A vehicle radio antenna comprising: a bearing bracket member forattachment to said vehicle; an elongated antenna member hingedly mountedintermediate its extremities in said bracket to swing in a verticalplane; a counterweight rigidly secured to the lower extremity of saidantenna member to maintain the latter normally vertical; a headedplunger member; spring means for urging the head of said plunger memberinto the path of movement of said counterweight so that contact with thelatter will depress said plunger; switch means, said switch means beingactuated by said plunger so as to be opened when the latter is depressedby said counterweight and closed when said counterweight swings out ofContact with said plunger; and a signal circuit including said switchmeans for giving a signal when said switch means closes.

5. In a vehicle radio antenna of the swinging, counterweight type, meansfor resisting swaying of said antenna and for giving a signal when lthelatter inclines from the vertical comprising: an indented projection onthe counterweight; a plunger having a rounded head positioned to engagethe indentation in said projection when said antenna is vertical; aspring urging said plunger toward said counterweight; a switch; andswitch closing means carried by said plunger and positioned to closesaid switch when said plunger is out of Contact with said counterweight.

LAWRENCE STONE, J R.

